toilets work off of siphon.more correctly it's the timely transfer of water from the tank to the bowl through the ports that starts the siphon and carrys the solids and water downstream,thus completing a flush.i also live in florida and due to lots of hard water everywhere can tell you that most likely the toilets are full of deposits and need to be replaced or are of poor quality.all of the toilets from home depot are trash i would suggest getting one from the factory or from a plumbing supply house.DO NOT GET A 1.28gpf...1.6gpf is still legal

We called Mr. Rooter because we had a leak from our kitchen sink and they responded quickly to my surprise. Mike Farnsworth shows up and gets right to work and doesn't give us an estimate for the work before he started. He ended up replacing a broken pipe in our basement that took 15 minutes and he plunged our tub and sink as well. He wasn't even here for an hour and he charged us $650 dollars! We refused to pay that much because it wasn't reasonable, so he took us to court and he ended up lying in front of a magistrate claiming he worked for 2 hours and did all these repairs, even though after he had left the sink was still leaking and the drains did not work at all!